Don't know what to do

Found out one of family members is pregnant with their third child I did congratulate them and is happy for them, at the same time I'm sad inside 😢and don't know what to do or say. We have been trying with no such luck. We quit trying and just went with it. It just makes me sad to see others have all the luck in world 🌎and us who have been waiting patiently hasn't happened at all. Me and my husband have talked about a big family that's how we both grew up. Just want some kind of answers as to why it's not happening.